mirror of
https://repo.or.cz/minetest_hudbars.git
synced 2024-11-30 19:03:49 +01:00
174 lines
9.1 KiB
Markdown
174 lines
9.1 KiB
Markdown
API documentation for the HUD bars mod 1.0.2
|
||
============================================
|
||
|
||
## Introduction
|
||
This API allows you to add, change, hide and unhide custom HUD bars for this mod.
|
||
|
||
## Overview
|
||
To give you a *very* brief overview over this API, here is the basic workflow on how to add your own custom HUD bar:
|
||
|
||
* Create images for your HUD bar
|
||
* Call `hb.register_hudbar` to make the definition of the HUD bar known to this mod
|
||
* Call `hb.init_hudbar` for each player for which you want to use previously defined HUD bar
|
||
* Use `hb.change_hudbar` whenever you need to change the values of a HUD bar of a certain player
|
||
* If you need it: Use `hb.hide_hudbar` and `hb.unhide_hudbar` to hide or unhide HUD bars of a certain player
|
||
|
||
## The basic rules
|
||
In order to use this API, you should be aware of a few basic rules in order to understand it:
|
||
|
||
* A HUD bar is an approximate graphical representation of the ratio of a current value and a maximum value, i.e. current health of 15 and maximum health of 20. A full HUD bar represents 100%, an empty HUD bar represents 0%.
|
||
* The current value must always be equal to or smaller then the maximum
|
||
* Both current value and maximum must not be smaller than 0
|
||
* Both current value and maximum must be real numbers. So no NaN, infinity, etc.
|
||
* The HUD bar will be hidden if the maximum equals 0. This is intentional.
|
||
* The health and breath HUD bars are hardcoded.
|
||
|
||
These are soft rules, the HUD bars mod will not enforce all of these.
|
||
But this mod has been programmed under the assumption that these rules are followed, for integrity.
|
||
|
||
## Adding a HUD bar
|
||
To make a new HUD bar known to this mod, you need …
|
||
|
||
* … an image of size 2×16 for the bar
|
||
* … an icon of size 16×16 (optional)
|
||
* … to register it with `hb.register_hudbar`
|
||
|
||
### Bar image
|
||
The image for the bar will be repeated horizontally to denote the “value” of the HUD bar.
|
||
It **must** be of size 2×16.
|
||
If neccessary, the image will be split vertically in half, and only the left half of the image
|
||
is displayed. So the final HUD bar will always be displayed on a per-pixel basis.
|
||
|
||
The default bar images are single-colored, but you can use other styles as well, for instance,
|
||
a vertical gradient.
|
||
|
||
### Icon
|
||
A 16×16 image shown left of the HUD bar. This is optional.
|
||
|
||
### `hb.register_hudbar(identifier, text_color, label, textures, default_start_value, default_start_max, default_start_hidden, format_string)`
|
||
This function registers a new custom HUD bar definition to the HUD bars mod, so it can be later used to be displayed, changed, hidden
|
||
and unhidden on a per-player basis.
|
||
Note this does not yet display the HUD bar.
|
||
|
||
The HUD bars will be displayed in a “first come, first serve” order. This mod does not allow fow a custom order or a way to set it
|
||
manually in a reliable way.
|
||
|
||
|
||
#### Parameters
|
||
* `identifier`: A globally unique internal name for the HUD bar, will be used later to refer to it. Please only rely on alphanumeric characters for now. The identifiers “`health`” and “`breath`” are used internally for the built-in health and breath bar, respectively. Please do not use these names.
|
||
* `text_color`: A 3-octet number defining the color of the text. The octets denote, in this order red, green and blue and range from `0x00` (complete lack of this component) to `0xFF` (full intensity of this component). Example: `0xFFFFFF` for white.
|
||
* `label`: A string which is displayed on the HUD bar itself to describe the HUD bar. Try to keep this string short.
|
||
* `textures`: A table with the following fields:
|
||
* `bar`: The file name of the bar image (as string).
|
||
* `icon`: The file name of the icon, as string. This field can be `nil`, in which case no icon will be used.
|
||
* `default_start_value`: If this HUD bar is added to a player, and no initial value is specified, this value will be used as initial current value
|
||
* `default_max_value`: If this HUD bar is added to a player, and no initial maximum value is specified, this value will be used as initial maximum value
|
||
* `default_start_hidden`: The HUD bar will be initially start hidden by default when added to a player. Use `hb.unhide_hudbar` to unhide it.
|
||
* `format_string`: This is optional; You can specify an alternative format string display the final text on the HUD bar. The default format string is “`%s: %d/%d`” (in this order: Label, current value, maximum value). See also the Lua documentation of `string.format`.
|
||
|
||
#### Return value
|
||
Always `nil`.
|
||
|
||
|
||
## Displaying a HUD bar
|
||
After a HUD bar has been registered, they are not yet displayed yet for any player. HUD bars must be
|
||
explicitly initialized on a per-player basis.
|
||
|
||
You probably want to do this in the `minetest.register_on_joinplayer`.
|
||
|
||
### `hb.init_hudbar(player, identifier, start_value, start_max, start_hidden)`
|
||
This function initialzes and activates a previously registered HUD bar and assigns it to a
|
||
certain client/player. This has only to be done once per player and after that, you can change
|
||
the values using `hb.change_hudbar`.
|
||
|
||
However, if `start_hidden` was set to `true` for the HUD bar (in `hb.register_hudbar`), the HUD bar
|
||
will initially be hidden, but the HUD elements are still sent to the client. Otherwise,
|
||
the HUD bar will be initially be shown to the player.
|
||
|
||
#### Parameters
|
||
* `player`: `ObjectRef` of the player to which the new HUD bar should be displayed to.
|
||
* `identifier`: The identifier of the HUD bar type, as specified in `hb.register_hudbar`.
|
||
* `start_value`: The initial current value of the HUD bar. This is optional, `default_start_value` of the registration function will be used, if this is `nil`.
|
||
* `start_max`: The initial maximum value of the HUD bar. This is optional, `default_start_max` of the registration function will be used, if this is `nil`
|
||
* `start_hidden`: Whether the HUD bar is initially hidden. This is optional, `default_start_hidden` of the registration function will be used as default
|
||
|
||
#### Return value
|
||
Always `nil`.
|
||
|
||
|
||
|
||
## Modifying a HUD bar
|
||
After a HUD bar has been added, you can change the current and maximum value on a per-player basis.
|
||
You use the function `hb.change_hudbar` for this.
|
||
|
||
### `hb.change_hudbar(player, identifier, new_value, new_max_value)`
|
||
Changes the values of an initialized HUD bar for a certain player. `new_value` and `new_max_value`
|
||
can be `nil`; if one of them is `nil`, that means the value is unchanged. If both values
|
||
are `nil`, this function is a no-op.
|
||
This function also tries minimize the amount of calls to `hud_change` of the Minetest Lua API, and
|
||
therefore, network traffic. `hud_change` is only called if it is actually needed, i.e. when the
|
||
actual length of the bar or the displayed string changed, so you do not have to worry about it.
|
||
|
||
#### Parameters
|
||
* `player`: `ObjectRef` of the player to which the HUD bar belongs to
|
||
* `identifier`: The identifier of the HUD bar type to change, as specified in `hb.register_hudbar`.
|
||
* `new_value`: The new current value of the HUD bar
|
||
* `new_max_value`: The new maximum value of the HUD bar
|
||
|
||
#### Return value
|
||
Always `nil`.
|
||
|
||
|
||
## Hiding and unhiding a HUD bar
|
||
You can also hide custom HUD bars, meaning they will not be displayed for a certain player. You can still
|
||
use `hb.change_hudbar` on a hidden HUD bar, the new values will be correctly displayed after the HUD bar
|
||
has been unhidden. Both functions will only call `hud_change` if there has been an actual change to avoid
|
||
unneccessary traffic.
|
||
|
||
Note that the hidden state of a HUD bar will *not* be saved by this mod on server shutdown, so you may need
|
||
to write your own routines for this or by setting the correct value for `start_hidden` when calling
|
||
`hb.init_hudbar`.
|
||
|
||
### `hb.hide_hudbar(player, identifier)`
|
||
Hides the specified HUD bar from the screen of the specified player.
|
||
|
||
#### Parameters
|
||
* `player`: `ObjectRef` of the player to which the HUD bar belongs to
|
||
* `identifier`: The identifier of the HUD bar type to hide, as specified in `hb.register_hudbar`.
|
||
|
||
#### Return value
|
||
Always `nil`.
|
||
|
||
|
||
### `hb.unhide_hudbar(player, identifier)`
|
||
Makes a previously hidden HUD bar visible again to a player.
|
||
|
||
#### Parameters
|
||
* `player`: `ObjectRef` of the player to which the HUD bar belongs to
|
||
* `identifier`: The identifier of the HUD bar type to unhide, as specified in `hb.register_hudbar`.
|
||
|
||
#### Return value
|
||
Always `nil`.
|
||
|
||
|
||
## Reading HUD bar information
|
||
It is also possible to read information about an active HUD bar.
|
||
|
||
### `hb.get_hudbar_state(player, identifier)`
|
||
Returns the current state of the active player's HUD bar.
|
||
|
||
#### Parameters
|
||
* `player`: `ObjectRef` of the player to which the HUD bar belongs to
|
||
* `identifier`: The identifier of the HUD bar type to hide, as specified in `hb.register_hudbar`.
|
||
|
||
#### Return value
|
||
A table which holds information on the current state of the HUD bar. Note the table is a deep
|
||
copy of the internal HUD bar state, it is *not* a reference; the information hold by the table is
|
||
only true for the moment you called this function. The fields of this table are:
|
||
|
||
* `value`: Current value of HUD bar.
|
||
* `max`: Current maximum value of HUD bar.
|
||
* `hidden`: Boolean denoting whether the HUD bar is hidden.
|
||
* `barlength`: The length of the HUD bar in pixels. This field is meaningless if the HUD bar is currently hidden.
|
||
* `text`: The text shown on the HUD bar. This fiels is meaningless if the HUD bar is currently hidden.
|